GHSA-rvmm-v933-jgxq

`ChartsController::actionGetNewUsersData()` at `/actions/charts/get-new-users-data` is missing a `requirePermission('viewUsers')` authorization check. Any authenticated control panel user, regardless of permissions beyond `accessCp`, can POST to this endpoint to receive time-series user registration counts for the entire site or for an arbitrary user group ID.

The `viewUsers` permission is consistently required throughout the control panel before exposing user-related data, but this action enforces only the base `accessCp` check inherited from the framework.

Each call returns the total count of users who joined the specified group in the requested period.

## Impact

Any control panel user with only `accessCp` permission can obtain the total number of registered users and their registration date distribution across any time window.

In installations with multiple editor roles, this allows a low-privilege control panel user to infer user group sizes and registration trends that would normally require the `viewUsers` permission to access.

No user PII (name, email, password) is disclosed; only aggregate counts and timestamps are returned. Confidentiality impact is low. No integrity or availability impact.